Roman Emperor. Noted for his fierce persecution of the Christians. The reign of Diocletian (284-305) marked an era both in the military and political history of the empire. Diocletian's name is associated with the last and most terrible of all the ten persecutions of the early Church. Nevertheless it is a fact that the Christians enjoyed peace and prosperity during the greater portion of his reign. The so-called Diocletian persecution should be attributed to the influence of his advisor Galerius; it continued for seven years after Diocletian's abdication. For more information , see the Catholic Encyclopedia articles on Diocletian and persecutions.